Amalgamator and concentrator



June 3, 1941. Q Q QVERTQN V2,244,429

AMALGAMATOR AND CONCENTRATOR Filed' April 29, 1940 Patented llune 3,1941 NiTED STATES PATENT ortica AMALGAMATOR AND fCONCENTR/ATOR ClarenceD. Overton, Los Angeles, Calif.

Application April 29, 1940, Serial No. 332,133

3 Claims.

The present invention relates generally to a method and apparatus forrecovering metallic gold from gold bearing ore, and more particularly tothe amalgamation and concentration of free gold, with the object, amongothers, of accomplishing the same in a manner which will effectively doaway with all danger of the flowering of the mercury and Waste thereofas well as of free gold.

It is well known in the practical art that anything in the way ofmethods, machines or apparatus for the above purpose, permitting ortending toward separation of the mercury into small particles, orflowering of the mercury as it is called, developes considerable loss inboth mercury and gold. In small particles, the gold and mercury may iindtheir way into, and outflow with, the dross or tailings. It is one ofthe primary purposes of the present invention to eliminate this loss bythe provision of a method and apparatus tending to keep the mercurytogether and prevent separation thereof, as well as insure intimatecontact therewith, of every particle of free gold in the ore handled.

A further object of the invention is the provision of a method andapparatus according to which every portion or particle of the oretreated is forced to pass through a body of mercury at a time when bothore and mercury are similarly and powerfully acted upon to bring abouttheir intimate churning or grinding together.

A further object of the invention is the maintenance of a body ofmercury in a manner dennitely presenting an axial or central areasubstantially removed from the perimeter of the body, and the feeding ofore, containing free gold, into the said axial or central area of themaintained body of mercury and thereafter conlined, during forcefulintermixing of the ore and mercury, against movement out of the mercuryexcept in a direction radially of the mercury body from its said centralarea to its perimeter, and in this way carry on thorough, eicientamalgamation in a manner which is novel both as to the method as well asto the apparatus.

A still further object is the provision of an apparatus of the abovecharacter which may be made in various sizes having diierent capacitiesand which will be equally efcient in all such sizes. Y

A still further object of the invention is the provision of an apparatusin which successful amalgamation and concentration may be carried outwith minimum power requirements, and with slow grinding of the ore andmercury in a more (Cl. R09 191) or less frictionless contact with themixing, churning or grinding parts or elements.

While appreciating that my invention is readily adaptable to numerousmodifications and changes, I will now describe the best mode so fardevised by me for its practical success, the

description in detail referring to the accompanying drawing,illustrating the invention and forming a part of this specication. Inthe drawing,

Figure 1 is a side elevation of the apparatus of this invention.

Figure 2 is a top plan view thereof with the upper gears removed.

Figure 3 is a vertical, sectional View taken centrally therethrough onthe line 3--3 of Figure l.

Figure 4 is a vertical, sectional view taken centrally therethroughalong a line at right angles to the section of Figure 3, and,

Figure 5 is a horizontal sectional View taken substantially on line 5--5of Figure l.

Referring now to the above figures of the drawing, I preferably utilizean upwardly opening, vertically cylindrical casing Il) within and uponthe base of which there is disposed a stationary or bottom grindingplate Il. This plate as plainly seen extends across the full diameter ofthe casing base and is to be formed of a hard, wear-resisting materialfor a reason which will presently appear.

AThe upper face of the ybottom plate Il forms a horizontal flat surfaceon which a plurality of hard steel grinding balls I2 are disposed,preferably in number to substantially cover the surface and at the sametime allow somewhat free movement of the balls for independent rotationon constantly varying axes under the effect of an upper grinding platei3 overlying, and resting of its own weight evenly upon, the grindingballs I2.

The upper grinding plate I3 is of substantially reduced diameter withrespect to the lower plate, and is supported in coaxial relation to thelatter upon the lower end of its axially upstanding shaft I4, so that anannular, upwardly opening channel I5 is thus formed between theperimeter of the upper grinding plate I3 and the casing wall. Thischannel, it will be noted, forms and affords the only communication fromthe space between the plates Il and I3 into the casing I0 above theplate I3.

The shaft I4 is hollow and forms a feed tube downwardly through whichthe ore from the mill is constantly fed from the lower end of the y tubeinto the axial or central area of the space between the grinding platesII and I3, since the lower end of the feed tube opens downwardly throughthe upper plate I3 and, as plainly seen in Figures 3 and 4, extendsbelow the plate I3 which it supports, in order to prevent crowding ofthe balls I2 below the feed tube where material is fed to the spacebetween the plates I I and I3. Obviously the ore so fed into the spacebetween the plates II and I3 is intimately intermixed with the mercury,maintained at a substantial level above the bottom plate I I.

The above action in the present apparatus means more than mere mixing ofthe ore and mercury. The freely revolving and rotating balls, which forman anti-friction supportfor the upper plate I3, actually grind the oreand mercury together slowly and thoroughly without danger of eithergetting away fromtheother'as long as they are in the space between theplates. In the course of the above action, the ore is of courseprevented from movement out of the mercury in any direction exceptradially from the center to the perimeter of the plates II and I3, andit is along this path that the mixture slowly nds its way to the outerannular channel I5 where it moves upwardly into the casing above theupper plate I3.

It is plain that in the aboveoperation every particle of free gold willlbe brought into intimate contact with the mercury with which itamalgamates. Thus as the mixture rises through the channel I5 aroundplate I3 the heavier amalgam will separate from the dross or tailings,the former passing upwardly along the inner surface of the wall ofcasing IB for discharge through a side outlet or concentrate take-olfI6; The tailings, being somewhat lighter, rise upwardly along the upperconical cover II of plate I3 to finally discharge through a dischargenipple I8 in communication with a tailings discharge pipe I9, saidnipple having its inner receiving end opening within the casing adjacentto the upper inner end of the cone I1.

'Ihe casing lil may have laterally outstanding flanges 2) atdiametrically opposite points of its upper open end. 'I'o theseflangesmay be bolted the end portions of a cross bar or bridge 2i. Thisbridge has an openingthrough which the hollow feed shaft I4 rises, andVforms a support for an upstanding bearing cage or cylinder 22- aroundshaft I4. In the cylinder 22 are upper and lower bearings 23 and 24, incontactv with the shaft Ill at vertically spaced points of the latter.

Above the bearing cylinder 22, the shaft I4 is shown with a fixed gear25 which may be of the bevel type to engage a similar gear 26 of reducedsize, on a drive shaft 2'I extending from, and actuated by, any suitablesource of power. However other types of gearing may be used, since thepresent apparatus lends itself to elcient operation with small powerrequirements.

The bridge 2| also serves as a support for rigidv pendant stirring arms28 in series at opposite sides of the shaft I4, with their lower endsterminating near the surface of the cone I'I at several points thereof,so as to prevent the tailings from building up on the cone surface andin this manner insuring ready discharge of said tailings through thedischarge pipe I9.

In order to maintain uniformfeed ofore into the space between thegrinding plates as previ# ously mentioned, I preferably utilize, withinthe feed shaft I4, means which, inconnection'with' this rotating shaft,will control such feed and at the same time prevent clogging thereof.

For the above purpose I may employ a stationary, twisted or spiral feedstrip or ribbon 29 within the feed shaft I4, which strip or ribbon maybe secured in any suitable manner as by anchoring the lower end of thesame to the bottom plate II. Any other suitable means may, however beused for this purpose, either stationary or movable of itself.

It is believed that, from the foregoing description, the advantages inoperation of the present apparatus will be readily recognized. Everyparticle of free gold is forced into intimate contact with the mercuryin an area in which ore and mercury are intermingled during slowrotation of the upper grinding disc or plate, and rotation and roamingof the grinding balls I2, well adapted to eiiicient functioning with lowpower demands and without danger of loss of free gold or throughflowering of the mercury.

The apparatus of this invention economical in its manufacture as well asits use, and is not only capable of a long effective life, but issingularly free of parts likely to need frequent repair orreplenishment, and is a fitting complement to the method it so wellcarries to effective conclusion.

Having thus fully described my invention, what I claim and desire to`secure by Letters'Patent is,

1. Incombination,` a casing, means forming a mercury space horizontallywithin the lower portion of the-casing including superimposed plates ofwhichy the upper plate is rotatable, with its perimeter spaced from thewall of the casing to form a mixture dischargechannel opening upwardlyinto they casing, balls freely disposed in said mercury space and uponwhich theupper plate rests, a hollow upright feed shaft rotating saidupper plate and -opening downwardly therethrough into the center of themercury space, an inverted cone atop the rotating upper plate having awide lower end onsaid plate and having a narrow upper end closelysurrounding the shaft at a point spaced vertically above the rotatingplate, said casing havinga concentrate take-off through itswall abovethe-upper plate, and a tailings discharge member extending radiallyinwardly through the upper portionpoflthe wall of the casing andY havingits inner receiving end opening'within the casing adjacent to the upperend of the cone where it surrounds the shaft.

2; In combination, acasing, means forming a mercury space horizontallywithin the lower portion of the casing including superimposed plates ofwhich the upper plate is rotatable' with its perimeter spaced from thewall of the casing to forma circumferential mixture discharge `channelopening upwardly into the casing, balls freely disposed in said mercurytspace and upon which the rotatable plate rests, and a hollow uprightfeed shaft rotating said upper plate and opening downwardly therethroughwith its lower end extending below the upper plate and projecting into-the center ofthe mercury space l to` prevent the balls from crowdinginthe lower discharge end of the said feed shaft.

3. In combination, a casing,` means forminga mercury space horizontallywithin the lower portion of the casing including superimposed ,platesofA which the upper plate is rotatable, with its perimeter spaced fromthe wall ofthe casing to form a mixture discharge channel openingupwardly intothe casing, balls freely disposed in said mercury space andupon Which the upper plate rests, a hollow upright feed shaft rotatingsaid upper plate and opening downwardly therethrough into the center ofthe mercury space, a cone atop the rotating upper plate and around theshaft, said casing having a concentrate takeoff through its Wall abovethe upper plate, a tailings discharge member extending through the upperportion of the Wall of the Casing and having its inner receiving endopening Within the 10

